block/blk-crypto-internal.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 /*
   3  * Copyright 2019 Google LLC
   4  */
   5
   6 #ifndef __LINUX_BLK_CRYPTO_INTERNAL_H
   7 #define __LINUX_BLK_CRYPTO_INTERNAL_H
   8
   9 #include <linux/bio.h>
  10 #include <linux/blk-mq.h>
  11
  12 /* Represents a crypto mode supported by blk-crypto  */
  13 struct blk_crypto_mode {
  14         const char *name; /* name of this mode, shown in sysfs */
  15         const char *cipher_str; /* crypto API name (for fallback case) */
  16         unsigned int keysize; /* key size in bytes */
  17         unsigned int ivsize; /* iv size in bytes */
  18 };
  19
  20 extern const struct blk_crypto_mode blk_crypto_modes[];
  21
  22 #ifdef CONFIG_BLK_INLINE_ENCRYPTION
  23
  24 int blk_crypto_sysfs_register(struct request_queue *q);
  25
  26 void blk_crypto_sysfs_unregister(struct request_queue *q);
  27
  28 void bio_crypt_dun_increment(u64 dun[BLK_CRYPTO_DUN_ARRAY_SIZE],
  29                              unsigned int inc);
  30
  31 bool bio_crypt_rq_ctx_compatible(struct request *rq, struct bio *bio);
  32
  33 bool bio_crypt_ctx_mergeable(struct bio_crypt_ctx *bc1, unsigned int bc1_bytes,
  34                              struct bio_crypt_ctx *bc2);
  35
  36 static inline bool bio_crypt_ctx_back_mergeable(struct request *req,
  37                                                 struct bio *bio)
  38 {
  39         return bio_crypt_ctx_mergeable(req->crypt_ctx, blk_rq_bytes(req),
  40                                        bio->bi_crypt_context);
  41 }
  42
  43 static inline bool bio_crypt_ctx_front_mergeable(struct request *req,
  44                                                  struct bio *bio)
  45 {
  46         return bio_crypt_ctx_mergeable(bio->bi_crypt_context,
  47                                        bio->bi_iter.bi_size, req->crypt_ctx);
  48 }
  49
  50 static inline bool bio_crypt_ctx_merge_rq(struct request *req,
  51                                           struct request *next)
  52 {
  53         return bio_crypt_ctx_mergeable(req->crypt_ctx, blk_rq_bytes(req),
  54                                        next->crypt_ctx);
  55 }
  56
  57 static inline void blk_crypto_rq_set_defaults(struct request *rq)
  58 {
  59         rq->crypt_ctx = NULL;
  60         rq->crypt_keyslot = NULL;
  61 }
  62
  63 static inline bool blk_crypto_rq_is_encrypted(struct request *rq)
  64 {
  65         return rq->crypt_ctx;
  66 }
  67
  68 #else /* CONFIG_BLK_INLINE_ENCRYPTION */
  69
  70 static inline int blk_crypto_sysfs_register(struct request_queue *q)
  71 {
  72         return 0;
  73 }
  74
  75 static inline void blk_crypto_sysfs_unregister(struct request_queue *q) { }
  76
  77 static inline bool bio_crypt_rq_ctx_compatible(struct request *rq,
  78                                                struct bio *bio)
  79 {
  80         return true;
  81 }
  82
  83 static inline bool bio_crypt_ctx_front_mergeable(struct request *req,
  84                                                  struct bio *bio)
  85 {
  86         return true;
  87 }
  88
  89 static inline bool bio_crypt_ctx_back_mergeable(struct request *req,
  90                                                 struct bio *bio)
  91 {
  92         return true;
  93 }
  94
  95 static inline bool bio_crypt_ctx_merge_rq(struct request *req,
  96                                           struct request *next)
  97 {
  98         return true;
  99 }
 100
 101 static inline void blk_crypto_rq_set_defaults(struct request *rq) { }
 102
 103 static inline bool blk_crypto_rq_is_encrypted(struct request *rq)
 104 {
 105         return false;
 106 }
 107
 108 #endif /* CONFIG_BLK_INLINE_ENCRYPTION */
 109
 110 void __bio_crypt_advance(struct bio *bio, unsigned int bytes);
 111 static inline void bio_crypt_advance(struct bio *bio, unsigned int bytes)
 112 {
 113         if (bio_has_crypt_ctx(bio))
 114                 __bio_crypt_advance(bio, bytes);
 115 }
 116
 117 void __bio_crypt_free_ctx(struct bio *bio);
 118 static inline void bio_crypt_free_ctx(struct bio *bio)
 119 {
 120         if (bio_has_crypt_ctx(bio))
 121                 __bio_crypt_free_ctx(bio);
 122 }
 123
 124 static inline void bio_crypt_do_front_merge(struct request *rq,
 125                                             struct bio *bio)
 126 {
 127 #ifdef CONFIG_BLK_INLINE_ENCRYPTION
 128         if (bio_has_crypt_ctx(bio))
 129                 memcpy(rq->crypt_ctx->bc_dun, bio->bi_crypt_context->bc_dun,
 130                        sizeof(rq->crypt_ctx->bc_dun));
 131 #endif
 132 }
 133
 134 bool __blk_crypto_bio_prep(struct bio **bio_ptr);
 135 static inline bool blk_crypto_bio_prep(struct bio **bio_ptr)
 136 {
 137         if (bio_has_crypt_ctx(*bio_ptr))
 138                 return __blk_crypto_bio_prep(bio_ptr);
 139         return true;
 140 }
 141
 142 blk_status_t __blk_crypto_init_request(struct request *rq);
 143 static inline blk_status_t blk_crypto_init_request(struct request *rq)
 144 {
 145         if (blk_crypto_rq_is_encrypted(rq))
 146                 return __blk_crypto_init_request(rq);
 147         return BLK_STS_OK;
 148 }
 149
 150 void __blk_crypto_free_request(struct request *rq);
 151 static inline void blk_crypto_free_request(struct request *rq)
 152 {
 153         if (blk_crypto_rq_is_encrypted(rq))
 154                 __blk_crypto_free_request(rq);
 155 }
 156
 157 int __blk_crypto_rq_bio_prep(struct request *rq, struct bio *bio,
 158                              gfp_t gfp_mask);
 159 /**
 160  * blk_crypto_rq_bio_prep - Prepare a request's crypt_ctx when its first bio
 161  *                          is inserted
 162  * @rq: The request to prepare
 163  * @bio: The first bio being inserted into the request
 164  * @gfp_mask: Memory allocation flags
 165  *
 166  * Return: 0 on success, -ENOMEM if out of memory.  -ENOMEM is only possible if
 167  *         @gfp_mask doesn't include %__GFP_DIRECT_RECLAIM.
 168  */
 169 static inline int blk_crypto_rq_bio_prep(struct request *rq, struct bio *bio,
 170                                          gfp_t gfp_mask)
 171 {
 172         if (bio_has_crypt_ctx(bio))
 173                 return __blk_crypto_rq_bio_prep(rq, bio, gfp_mask);
 174         return 0;
 175 }
 176
 177 /**
 178  * blk_crypto_insert_cloned_request - Prepare a cloned request to be inserted
 179  *                                    into a request queue.
 180  * @rq: the request being queued
 181  *
 182  * Return: BLK_STS_OK on success, nonzero on error.
 183  */
 184 static inline blk_status_t blk_crypto_insert_cloned_request(struct request *rq)
 185 {
 186
 187         if (blk_crypto_rq_is_encrypted(rq))
 188                 return blk_crypto_init_request(rq);
 189         return BLK_STS_OK;
 190 }
 191
 192 #ifdef CONFIG_BLK_INLINE_ENCRYPTION_FALLBACK
 193
 194 int blk_crypto_fallback_start_using_mode(enum blk_crypto_mode_num mode_num);
 195
 196 bool blk_crypto_fallback_bio_prep(struct bio **bio_ptr);
 197
 198 int blk_crypto_fallback_evict_key(const struct blk_crypto_key *key);
 199
 200 #else /* CONFIG_BLK_INLINE_ENCRYPTION_FALLBACK */
 201
 202 static inline int
 203 blk_crypto_fallback_start_using_mode(enum blk_crypto_mode_num mode_num)
 204 {
 205         pr_warn_once("crypto API fallback is disabled\n");
 206         return -ENOPKG;
 207 }
 208
 209 static inline bool blk_crypto_fallback_bio_prep(struct bio **bio_ptr)
 210 {
 211         pr_warn_once("crypto API fallback disabled; failing request.\n");
 212         (*bio_ptr)->bi_status = BLK_STS_NOTSUPP;
 213         return false;
 214 }
 215
 216 static inline int
 217 blk_crypto_fallback_evict_key(const struct blk_crypto_key *key)
 218 {
 219         return 0;
 220 }
 221
 222 #endif /* CONFIG_BLK_INLINE_ENCRYPTION_FALLBACK */
 223
 224 #endif /* __LINUX_BLK_CRYPTO_INTERNAL_H */